Process for the continuous, even dyeing of cotton piece goods containing portions of abnormal fibers

ABSTRACT

Process for the continuous dyeing of cotton piece goods containing portions of abnormal fibers, by impregnating the textile material for the purpose of covering these irregularities with a padding liquor which contains - in addition to suitable dyestuffs or components of developing dyestuffs - a cellulose ether, and then fixing the dyestuffs evenly on the fiber surface while precipitating (coagulating) said cellulose ether optionally with the action of the completing component for the development of the dyestuffs, by treating the goods with a solution of a salt or acid salt of a polyvalent metal or cation-active adjuvant.

United States Patent [191 Lehinant et al.

[451 Sept. 16, 1975 [75] Inventors: Armand Lehinant,

Offenbach(Main); Hans-Peter Maier, Sulzbach, both of Germany [73] Assignee: Hoechst Aktiengesellschaft,

Frankfurt am Main, Germany [22] Filed: Dec. 26, 1972 [21] Appl. No.: 318,193

[30] Foreign Application Priority Data Dec. 27, 1971 Germany 2164734 [52] US. Cl. 8/30; 8/18; 8/42; 8/79; 8/91 [51] Int. Cl. D06P l/36 [58] Field of Search 8/29, 30, 31, 91, 18

[56] References Cited UNITED STATES PATENTS 2,215,196 9/1940 Schlack 8/29 3,496,007 2/1970 Miyamoto 8/30 X OTHER PUBLICATIONS Gagliardi, American Dyestufi' Reporter, Jan. 22, 1962 pp. 31-40.

Primary Examiner-Donald Levy Attorney, Agent, or F irm-Curtis, Morris & Safford [57 ABSTRACT Process for the continuous dyeing of cotton piece goods containing portions of abnormal fibers, by impregnating the textile material for the purpose of covering these irregularities with a padding liquor which contains in addition to suitable dyestuffs or components of developing dyestuffs a cellulose ether, and then fixing the dyestuffs evenly on the fiber surface while precipitating (coagulating) said cellulose ether optionally with the action of the completing compo nent for the development of the dyestuffs, by treating the goods with a solution of a salt or acid salt of a polyvalent metal or cation-active adjuvant.

3 Claims, No Drawings PROCESS FOR THE CONTINUOUS, EVEN DYEING OF COTTON PIECE GOODS CONTAINING PORTIONS OF ABNORMAL FIBERS The present invention relates to a process for the continuous, even dyeing of cotton piece goods containing portions of abnormal fibers.

In the textile industry, various, mostly undesirable side effects arise when treating cotton which contains portions of abnormal fibers. Picked cotton always contains minor or major portions of immature or dead fibers which can especially be found in cotton of mean qualities, above all when the picking had been effected with machines.

As compared with normal fibers, immature or dead cotton fibers have a different morphology (crosssection, twist, wallthickness, staple-length) and a different swelling capacity which determines their behaviour in the dyeing process. V

When cotton is prepared, for example, carded, the abnormal fibers are locally amassed and form neps by sticking together. When being dyed, this immature, portion of the fiber material remains undyed and appears as fair neps on the fully dyed material.

Because of its high tendency to form neps immature cotton may adversely affect the dyeing results. Mean cotton qualities and mechanically picked cotton are especially affected by those negative effects as to the appearance of the goods.

It is known that the mercerization or treatment in caustic soda solution of the textile material before or after dyeing modifies the power of the immature cotton fibers of absorbing dyestuffs in such a manner that the neps mentioned above do not appear any more or only slightly on the material dyed. However, the mercerization or treatment in caustic soda solution of the material and the following processes for removing caustic soda often are too great an operational expenditure (cf. Textil-Praxis, 1965, No. 5, pages 406 410).

Now, it was found that in the case of cotton piece goods abnormal, i.e. immature or dead, fibrous portions can be dyed continuously, covered in their shade and thus made mostly imperceptible without additional operational steps and at the same time as the normally matured and developed fibers, by impregnating the textile material in the scope of the usual dyeing operation for the purpose of covering these irregularities with a padding liquor which contains in addition to suitable dyestuffs or components of developing dyestuffs a cellulose ether and then fixing the dyestuffs evenly on the fiber surface while precipitating (coagulating) said cellulose ether, optionally with theaction of the completing component for the development of the dyestuffs, by treating the goods with a solution of a salt or acid salt of a polyvalent metal or cation-active adjuvant.

The process of the invention can be carried out due to the fact that cellulose ethers are water-soluble and have affinity towards the same dyestuff classes as cellulose itself since they are its derivatives. They can, therefore, be dyed at the same time and in the same shade as cellulose and can be added to a padding liquor in any form By the action of aqueous solutions of the salts or acid salts of polyvalent metals, for example, aluminium or zirconium, especially, however, aluminium sulfate, or of cation-active substances, for example, on the basis of quaternary ammonium compounds, these cellulose ethers are coagulated or precipitated on the fiber, i.e. fixed in a water-insoluble manner. The cellulose ether mainly used in this invention is sodium carboxymethyl cellulose which can be incorparated as finishing agent into the dyestuffs or the dyestuff components, preferably the coupling components.

The cellulose ethers fixed in accordance with the invention have, besides their capacity of covering the neps, a finishing effect with regard to stiffness and filling of the textile article, which effect is adjustable and washproof. This effect is of considerable benefit for the cotton qualities mentioned and can be considered as distinct advantage of the provided process because it makes a following finishing often completely unnecessary. The fastness properties of the dyeings are not adversely affected by the cellulose ethers used, and as far as the rubbing propertyis concerned, it is even improved owing to a smoothing effect. Surprisingly, those dyeings resist with respect to the filling effect to repeated household washings applying the usual alkali concentrations.

To obtain homogeneous padding liquors for use according to, the invention, it is advantageous to mix a stock solution of the cellulose ethers (in the form of sodium carboxymethylcellulose) in the ratio of 1:100 (l or 2:.100 (2%) and to add this solution in the corresponding amount to the padding liquor. The stock solution is prepared by introducing the product as powder or as granules into cold soft water while stirring. After one or two hours the solution is free from lumps and is homogeneous. The cellulose ethers may also directly be strewed into the padding liquor, but in this case its temperature should not be above 30C because lumps are formed when introducing into hot water.

According to this invention, 0.75 to 3 g, preferably, however, 1.5 to 2 g of the cellulose ethers are used per liter of padding liquor, which corresponds to to 200 ml of the 1 percent stock solution per liter. Padding liquors of this concentration have a medium viscosity; the thickening effect of the cellulose ethers highly reduces the undesired dyestuff migration during the drying or dwelling period. The cellulose ethers do not form foam and act as protective colloids with regard to the other constituents of the liquid, which effect is very useful for the stability of the liquid. Using the amounts of cellulose ethers mentioned, the portions of abnormal cotton fibers are completely covered by the dyestuff, the material is given a full handle without a hard board-like feel.

As it has been described, the cellulose ethers, for example, carboxymethyl cellulose, react in the process of the invention with the ions of polyvalent metals while forming stable, insoluble coagulates. When using the cellulose ethers now in padding liquors containing dyestuffs and precipitating these substances on the fiber via a passage through the solution of a metal salt, preferably of aluminium sulfate, this precipitation is dyed in the same shade as the cotton. Such a fixing process can easily be inserted in most of the cases in the different after-treatment operations.

If the liquor pick-up is the same as in the padding process, 2 g of crystalline aluminium sulfate (Al (SO 18 P1 0) are required for l g of carboxymethyl cellulose in the padding liquor to precipitate the latter on the fiber. Aluminium sulfate has an acid reaction because of hydrolysis and serves, at the same time, as neutralizing agent by which reason in the case of using alkaline dyestuff liquors additional amounts of this precipitating agent are necessary. When fixing intermediately dried material, 1.4 g of crystalline aluminium sulfate per ml of sodium hydroxide solution (32.5 if the liquor pickup is equal. This calculation is made only if intermediately dried material is slop-padded on the" foulard.

When treating moist material with the aluminium sulfate solution according'to the roller box method, in the first box of the open-width washingdevice using solutions of 2 to g/l of crystalline aluminium sulfate, sufficient excess amounts of precipitating agent are present due to the higher goods-to-liquor ratio; the liquor must then be fed adequately with the agent according to the through-put of materialplt is useful to'prepare from crystalline aluminium sulfate too a stock-solution of known content, for example, 200 g/l. v

The dyeings of the invention can be prepared, for example, using reactive dyestuffs, insoluble azo dyestuffs formed on the fiber or pigment dyestuffs solubilized and precipitated thereafter on the fiber.

Among the series of reactive dyestuffs all assortments of this dyestuff class determined for dyeing cellulose fibers are taken into account regardless of the nature of their fiber-reactive group. Suitable dyestuffs for the process of the invention are reactive dyestuffs, especially those of the type of sulfatoethylsulfone .compounds or those the reactive constituents of which form a free vinylsulfone group under the action of alkali. In this regard there may also be mentioned dyestuffs conta'inin g B-( 2 ,2, 3 ,3-tetrafluorocyclobutyl acryloylamino groups, moreover dichloroquinoxaline, dichlorotriazine or monoand dihalogeno-pyrimidine groups. 3 v

The reactive dyestuffs are fixed in the process of this invention according to the pad-dwell method which leads to good color yields also on unmercerized cotton. In this case, the cellulose ether is added to the padding liquor and the alkali is added in usual'manner or'gradually charged in doses in the course of the dyeing operation. At the end of the dwelling process the material is passed, for example, according to the roller box method in the first box of the open-width washing device, through a cold bath containing the solution of can additionally be obtained by the formation of the corresponding metal s'oaps when the padded material passes through the precipitating bath containing the aluminiumor zirconium salts.

In the claimed process, insoluble azo dyestuffs of the coupling and diazo components are developed on the fiber according to the twobath pad-drying method, the carboxymethyl cellulose being added to the hot bath containing the coupling component. The protective colloids normally used in these impregnation baths can often be spared as the cellulose ether functions itself as anionic colloid. The aluminium sulfate (and in the case of diazo dyeings this alone used as the precipitating agent) is added to the developing bath containing the diazo component. Part of the suitable diazo compounds in the form of the stabilized fast colour salts however contains aluminium salts alkaline binding agent and therefore smaller amounts of aluminium sulfate are sufficient in some cases or not necessary at all, for example, with the commercial standards of compounds having the Colour Index Numbers 37,010; 37,195 and 37,075. I

The after-treatment is effected in this case by airpa ssage, hot-water-passage (C), rinsing in warm water and soaping on the open-width washing device. The soapi ng baths do not contain adjuvants of the usual sequestring agents. i

"Another possibility to prepare dyeings covering neps is to coagulate the carboxymethyl cellulose and to make it insoluble not by the action of metal ions but with cationicadjuvants especially on the basis of quaternary ammonium bases, for example, of the type of alkyl-dimethyl-benzyl-ammoniumchloride. The material is padded with the carboxymethylcellulose (l-2 g/l), dried and slop-padded with a solution of pigment dyestuffs reversibly solubilized, for example, according to German Pat.*Nos. 1,265,700; 1,269,587; 1,297,071

and 1,297,073 and of l 2 g/l of the said cationic product, rinsed and dried.

The following Examples illustrate the invention, the parts and'percent'ages being by weight unless stated otherwise:

EXAMPLE 1 o i l o NH-CO-CH ocH,

ml of a 1 percent aqueous solution of sodium carboxymethyl cellulose and 12 ml of a sodium hydroxide solution (of 32.5 which was charged gradually to the dyestuff solution by means of a dosage device during padding operation.

The textile material so treated was now rolled up at moist state, enveloped in a plastic sheet and allowed to dwell at room temperature for 6 hours.

Thereafter, the material was passed in the first box of an open-width washing device through a cold aqueous bath which contained 5 g/l of crystalline aluminium sulfate AI (SO 18 B 0, in such a'rnanner" that thequor could act on the material for about 20 seconds. In the following boxes of the washing device the dyed material was passed through warm and cold rinsing baths. A blue dyeing of good nep covering effect and of a full feel of the material was obtained. The above dyestuff is disclosed in US. Pat. No. 3,843,318, Example 7.

EXAMPLE 2 In an analogous manner as described in Example 1, a dyeing was prepared using, however, 20 g/l of the reactive dyestuff of the formula A brilliant blue dyeing having a good nep covering ef' fect was obtained. The above dyestuff is disclosed in US. Pat. No. 3,843,318, Example 6.

EXAMPLE 3 In an analogous manner as described in Example 1, a dyeing was prepared using 20 g/l of the reactive dyestuff of the formula A navy-blue dyeing of medium depth having a good nep covering effect was obtained.

EXAMPLE 4 To prepare a cotton dyeing in an analogous manner as described in Example 1, 20 g/l of the reactive dyestuff of the formula so u were used. A brilliant blue shade having a good nepcovering effect was obtained on the material.

EXAMPLE 5 A brilliant orange dyeing having a good nep covering effect was obtained when the dyeing was carried out in an analogous manner as described in Example 1 using, instead of the dyestuff mentioned therein, in this case 20 g/l of the reactive dyestuff of the formula The above dyestuff is disclosed in US. Pat. No. 3,843,318, Example 9.

EXAMPLE 6 In an analogous manner as described in Example 1 a dyeing was prepared using, however, 20 g/l of the reactive dyestuff of the formula so n TH NH-CO A brillant red dyeing having a good nep covering effect was obtained.

EXAMPLE 7 fillings.

(Azoic Coupling Component l C.l-No. 37510), were dissolved with 18 ml of a sodium hydroxide solution (of 32.5 and 150 ml of a 1 percent aqueous solution of sodium carboxy-methylcellulose at boiling temperature. The solution so obtained was boiled with direct steam for a short while and was adjusted to 1 liter of final volume by adding boiling water. After padding, the material so impregnated was dried intermediately and piled up. Then, the material was slop-padded with the same liquor pick-up with a cold liquor which contained per liter of water:

44 g of the diazonium compound from the amine of the formula Cl- NH (Azoic Diazo Component 17 C.I.No. 37055),

4 g of a non-ionic dispersing agent on the basis of the reaction product of 1 mol of stearyl alcohol with 25 mols of ethylene oxide, containing percent of polyethylene glycol of the molar weight of about 6000 and 18 g of crystalline aluminium sulfate Al (SO l8 H20.

Subsequently, the dyed material was passed, after an air passage of 30 seconds at room temperature, through hot water of 70C and further rinsing procedures followed. When soaping at boiling temperature (if necessary) no sequestring agents and a reduced amount of alkali were used.

A full, brilliant scarlet dyeing having a good covering effect as to immature fibers and a full feel of the goods were obtained. Without the use of the cellulose ether,

8 hardly any nep covering of the dyeing with this azocombination would result,

EXAMPLE 8 A brilliant red dyeing was obtained when pad-dyeing in an analogous manner as described in Example 8 and using as coupling component 14 g of the compound of formula v CO-NH -0c n.

(Azoic Coupling Component 46 C.I-No. 37559), dissolved in 14 ml of a sodium hydroxide solution (of 32.5 and as diazo component 45 g of the diazonium compound from the amine of formula (Azoic Diazo Component 33 C]. No. 37075).

The amounts of carboxy-methyl cellulose, dispersing agent and aluminium sulfate were the same.

We claim:

1. In a process for the continuous level dyeing of cotton piece goods containing portions of abnormal fibers, the improvement, for the purpose of covering these irregularities, which comprises: impregnating the textile material with an alkaline padding liquor which contains carboxymethyl cellulose and a reactive dyestuff or components of azo developing dyestuff; and then, either after fixation of the reactive dyestuff or simultaneously with the completion of development of the azo dyestuff, precipitating the dyed carboxymethyl cellulose on the fiber surface by treating the goods with a solution of a salt or acid salt of a polyvalent metal or a cationic adjuvant containing quaternary ammonium compounds.

2. A process as claimed in claim 1, wherein the carboxymethyl cellulose is incorporated into the dyestuffs or dyestuff components, preferably into the coupling components, as finishing agent.

3. A process as claimed in claim 1, wherein as precipitating agent a salt or acid salt of aluminium or circonium, preferably aluminium sulfate is used. 

1. IN A PROCESS FOR THE CONTINUOUS LEVEL DYEING OF COTTON PIECE GOODS CONTAINING PORTIONS OF ABNORMAL FIBERS, THE IMPROVEMENT, FOR THE PURPOSE OF COVERING THESE IRREGULARTIES, WHICH COMPRISES: IMPREGNATING THE TEXTILE MATERIAL WITH AN ALKALINE PADDING LIQUOR WHICH CONTAINS CARBOXYMETHYL CELLULOSE AND REACTIVE DYESTUFF OR COMPONENTS OF AZO DEVELOPING DYESTUFF: AND THEN, EITHER AFTER FIXATION OF THE REACTIVE DYESTUF OR SIMULTANEOUSLY WITH THE COMPLETION OF DEVELOPMENT OF THE AZO DYESTUFF, PRECIPITATING THE DYED CARBOXYMETHYL CELLULOSE ON THE FIBER SURFACE BY TREATING THE GOODS WITH A SOLUTION OF A SALT OR ACID SALT OF A POLYVALENT METAL OR CATIONC ADJUVANT CONTAINING QUATERNARY AMMONIUM COMPOUNDS.
 2. A process as claimed in claim 1, wherein the carboxymethyl cellulose is incorporated into the dyestuffs or dyestuff components, preferably into the coupling components, as finishing agent.
 3. A process as claimed in claim 1, wherein as precipitating agent a salt or acid salt of aluminium or circonium, preferably aluminium sulfate is used. 